Sighting device for artillery guns

ABSTRACT

A sighting device for the alignment of an artillery gun in the terrain so that the elevation axis of the gun coincides with the horizontal plane and the azimuth axis extends perpendicularly thereto. The present sighting device provides for a correction of the azimuth angle and the elevation angle values of the gun to which the weapon is set by taking into account the magnitude of the swing of the weapon&#39;&#39;s own coordinate system relative to the terrain coordinate system. First parts of the sighting device are connected rigidly with respect to the gun axis while second parts are adjustable to the horizontal plane of the terrain. The difference in position between the first and second parts is evaluated and provides a measure for the correction values.

United States Patent [191 Michalak [451 Dec. 3, 1974 1 SIGHTING DEVICE FOR ARTILLERY GUNS [75] Inventor: Wilhelm Michalak, Niederbiel,

Germany [73] Assignee: Ernst Leitz GmbH, Wetzlar,

Germany [22] Filed: Nov. 3, 1972 [2]] App]. No.: 303,514

[30] Foreign Application Priority Data Nov. 25, 1971 Germany 2158428 [52] US. Cl. 33/240 [51] Int. Cl. F41g 1/44 [58] Field of Search 33/240 [56] References Cited UNITED STATES PATENTS 950,078 2/1910 Olsson 33/240 1,361,781 12/1920 Schneider 33/240 1,385,153 7/1921 Schmidt 89/41 1,635.763 7/1927 Otto 33/240 FOREIGN PATENTS OR APPLICATIONS 84,203 8/1935 Sweden 33/240 Primary Examiner-Louis R. Prince Assistant ExaminerRichard R. Stearns Attorney, Agent, or FirmKrafft & Wells ['5 7] ABSTRACT A sighting device for the alignment of an artillery gun in the terrain so that the elevation axis of the gun coincides with the horizontal plane and the azimuth axis extends perpendicularly thereto. The present sighting device provides for a correction of the azimuth angle and the elevation angle values of the gun to which the weapon is set by taking into account the magnitude of the swing of the weapons own coordinate system relative to the terrain coordinate system. First parts of the sighting device are connected rigidly with respect to the gun axis while second parts are adjustable to the horizontal plane of the terrain. The difference in position between the first and second parts is evaluated and provides a measure for the correction values.

9 Claims, 4 Drawing Figures PMENTL all SHEET 3 BF 3 SIGIITING DEVICE FOR ARTILLERY GUNS BACKGROUND OF THE INVENTION 'The invention relates to a sighting device for guns.

I tal plane in the direction of the target point, and when the bore axis possesses an inclination relative to the horizontal plane determined by ballistics.

The positions of the weapon and the target are measured in relation to a coordinate system defined in the horizontal plane. With the aid of the sighting arrangement, the direction of the bore axis is to be set on the target by rotation about the azimuth axis and the elevation axis. The sight angle values to be set relate to the three-dimensional coordinate system which is built up on the horizontal plane, but the angle values indicated about the azimuth axis and elevation axis relate to a three-dimensional coordinate system which is built up on a plane set by the weapon itself. The angle values measured in the terrain can be transferred directly to the weapon only when the plane defined by the azimuth axis and the elevation axis stands perpendicular to the horizontal plane. Such an alignment of the weapon in the terrain is in general not possible, or can only be achieved with great difficulty. A swing of the weapons own coordinate system in relation to the terrain coordinate system built up on the horizontal plane, however, causes all angle values seton the weapon to be effective only as the magnitude of their projection on to the terrain coordinate system. The transformation is difficult, and presupposes a knowledge of the magnitude of the swing.

Some sighting arrangements are connected rigidly in alignment with the elevation axis, but at the same time are mounted with a gun sight containing a panoramic telescope by means of a Cardan joint to be rotatable about the elevation axis and tiltable in relation to the elevation axis. The target is sighted through the panoramic telescope. An inclination, if present, of the elevation axis iscompensated by levelling of the gun sight, and tilting by means of the Cardan joint is converted into rotation of the panoramic telescope about its vertical axis in the gun sight of the sighting arrangement.

The angle of sighting of the weapon is re-set until the target or the aiming point is again sighted. By levelling and resetting many times, the true correction of the inclination of the elevation axis towards the side may be in respect of height is also necessary. It has thus been proposed to measure the angle of elevation .by the inclination of a shank of the Cardan joint turned about the elevation axis, in relation to the levelled surface of the gun sight, so that correction of the angle of elevation becomes unnecessary.

In spite of mechanical transformation of the angle values measured at the weapon into the terrain coordinate system, sighting arrangements may still in general be found to be relatively inaccurate and only applicable under favorable conditions to the indirect aiming of very long range artillery weapons. Errors may lie on the one hand in the mechanical design, and on the other hand in the employed angular measuring systems.

It is, therefore, an object of the invention to provide an improved mechanical design of a sighting device with automatic azimuth correction and an elevation angle measured in a plane perpendicular to the horizontal plane. It is a further object to provide a sighting device which in connection with an adequate angle value measuring device meets even extreme precision requirements. And it is another object to provide a sighting device with digital indication of the angle values.

SUMMARY OF THE INVENTION The above stated objects are attained by providing a sighting device for an artillery weapon, comprising a shaft to be aligned parallel to an axis of elevation of such weapon, a universal joint having a first part rigidly carried by the shaft, the universal joint being received in a housing comprising a body portion and a head which is rotatable relatively to the body portion and which is connected to the universal joint. The housing is provided with spirit levels to permit the housing so to be levelled that the axis of rotation extends in a vertical direction. An elongate second part of the universal joint is mounted on the first part to be rotatable relatively thereto about an axis perpendicular to the longitudinal axis of the shaft and is mounted on a mounting portion of the head to be rotatable about the longitudinal axis of the second part. An angle measuring device comprising a first element carried by the second part is situated within the universal joint and extends transversely of the longitudinal axis of the second part, and a second element which is rotatable relatively to the first element and which is rigidly connected to the mounting portion. The first and second elements each are provided with an indicator and each has a center on the longitudinal axis of the second part. The two elemerits together define a plane in which is measure, in a coordinate system defined by the sighting device, the angle of elevation of locating means on the head for 10- cating a telescope. The telescope comprises a further angle measuring device to measure the azimuth of the telescope in the same coordinate system.

Conveniently, the mounting portion comprises a lug integral with the remainder of the head, the remainder carrying the locator.

Preferably, the origins are situated substantially at the point of intersection of the longitudinal axis of the second part and the perpendicular axis.

Advantageously, the universal joint further com prises a third part connected between the first part and the housing, the third part being mounted to be rotatable relatively to the first part and being provided with two spaced apart bores having a common axis and receiving mounting means of the housing to permit the housing to rotate about the common axis of the bores, the common axis coinciding with the perpendicular axis.

The device may comprise a manually operable drive to cause the housing to rotate relatively to the third part about said perpendicular axis.

The device may comprise a manually operable driving device to cause the third part to rotate relatively to the first part about the longitudinal axis of the shaft.

Preferably, at least one of the parts of the universal joint comprises a part-spherical socket member.

Conveniently, the angle measuring devices each comprise an electrical signal generator to generate electrical signals indicative of the angles measured by the measuring device, and a digital indicator to provide a visual indication of the angles.

In one construction the angle measuring devices are each provided with visible graduations and with an optical image conductor to conduct an image of the graduations to a respective reading location, and preferably the reading locations are situated on a common indicating panel.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more readily comprehended from the following description when taken in conjunction with the appending drawings, wherein FIG. 1 shows an overall view of a sighting arrangement,

FIG. 2 shows a longitudinal ing arrangement,

FIG. 3 shows a cross-section through the housing,

taken on the line IIIIII in FIG. 2, and

FIG. 4 is a detailed showing of FIG. 3 with the addition of an image conductor of the angle graduations.

DESCRIPTION OF THE PREFERRED EMBODIMENT From FIG. 1 it is evident that the entire sighting arrangement is put together from three functional groups. These are a gun sight holder 100, a housing constructed as an assembly 200 and a panoramic telescope 300.

The gun sight holder 100 is secured with lever arms 101 and a support 102 on a gun mount (not shown). The mount is equipped with an adjusting device which permits adjustment of the sighting arrangement, thereby adjusting the axes 201, 2001 and 2071 of said arrangement relative to the axes of the gun (these are the elevation axis, the bore axis of the gun barrel and the azimuth axis) in such a way that the coordinated axes extend in parallel, namely,

201 parallel to the eleyation axis,

2001 parallel to the azimuth axis, and

2071 parallel to the bore axis.

The sighting arrangement is connected with a pin (not shown) parallel to the elevation axis by a drive axle 201. The two must be adjusted to be in alignment with one another. In general, the drive axle 201 is fitted as an extension of the pin; however, there is also possible a parallel displacement between the two. A scale 202 with a vernier 103 is provided on the gun sight holder 100. The scale is connected by a spur wheel drive 2020 (FIG. 2) with the drive axle 201, and is driven by the latter for example with a transmission ratio of 4:1. The vernier 103 is rigid relatively to the longitudinal levelling system, but is moved (levelled) with the latter relatively to the gun mount and makes possible auxiliary reading-off of the angle of elevation section through the sightwith an accuracy of I mil, in the weapon s own coordinate system.

The measurement of the angle of elevation of the gun in a plane perpendicular to the horizontal takes place within the housing assembly 200, which is secured to be movable relatively to the gun sight holder in a cap bearing 104 and is coupled rigidly on to the drive axle 201. The housing assembly can be turned by a manually operable driving device in the form of an operating knob 105 about the drive axle 201, and by manually operable drive means in the form of an operating knob 203 about an axis perpendicular thereto (FIG. 2), so

that independently of the inclination of the drive axle 201, leveling of the housing assembly is always possible with the aid of two spirit levels 204 fitted to one another at a head 215 of the housing assembly 200.

A Cardan universal joint 205 is mounted in the housing assembly 200. The middle of the Cardan joint is disposed at the point of intersection of the extended axis of rotation 2011 of the drive axle 201 with the longitudinal axis 2001 of the housing assembly 200 passing through the middle of the cup bearing 104. The Cardan joint is built up from a first joint part 206, which transfers the rotation about the elevation axis, and a second joint part 207 mounted therein. The two joint parts are tiltable relatively to one another perpendicularly to the axis about an axis 2071, which likewise passes through the middle of the Cardan joint. The first joint part 206 is embraced by a third joint part 208, on the inner surface 209 of which it is mounted rotatably about the axis 2011. The outer surface of the joint part 208 has in the plane which the axis 2071 describes during rotation about the axis 2011, two diametrically opposite coaxial bores 210 and 211. In these bores, the housing assembly 200 is rotatably suspended by means of bolts 212 and 213. All joint parts 206, 207 and 208 are, as illustrated, constructed as part-spherical ball sockets so that the Cardan joint receives a high mechanical stability.

Besides the rotation about the axis 2071, the joint part 207 is also rotatable about its longitudinal axis 2072. For this purpose it is mounted in a mounting portion in the form ofa lug or lever arm 2l4, which is perpendicular to the longitudinal axis 2072 of the joint part 207 and is likewise rigidly connected at right angles with the head 215 of the housing assembly 200. The head 215 is on its part rotatable about the longitudinal axis 2001 of the housing assembly 200 and provided with locating means 216 for the panoramic telescope 300.

Inside the joint part 207 a plate 217 with an angular graduation is fitted in a plane perpendicular to the longitudinal axis 2072 and connected rigidly with the joint part 207 (FIG. 3). A second plate 218 with a reference graduation and rigidly connected with the lever arm 214 by means of a pin member is parallel thereto. The graduations can be numbered angular graduations for direct reading for example by means of image conductor cables with imaging optics or coded graduations, which are evaluated photoelectrically (as disclosed in German Pat. Specification No. 1,301,916). The center of the graduations of the two plates are disposed substantially at the point of intersection of the three axes of rotation 2011, 2071 and 2001. It is, however, also possible as a variation to arrange the plates with the angular graduations in a position displaced in a direction parallel to the axis 2072.

The panoramic telescope 300 is so adjusted in the eating means 216 of the head 215 of the housing assembly 200 that in its null position it points with its viewing direction parallel to the bore axis of the weapon. During the swinging of the weapon, the azimuth is likewise digitally indicated, for example by means of two coded azimuth circles fitted perpendicular to the axis of rotation of the panoramic telescope 300, and the corresponding electronic circuitry. If desired, optical image conducting means such as cables are employed to conduct images of the graduations of the respective angle measuring devices to a common indicator panel. As long as the housing assembly 200 carrying the panoramic telescope 300 is not levelled, the indicated azimuth is, however, not corrected as regards rotation in the horizontal plane.

An inclination of the housing assembly 200 in the longitudinal direction is compensated by means of a worm drive 106, (as shown in FIG. 2) which is connected with the operating knob 105 and which acts on the joint part 208, and by means of the bolts 212 and 213, which transfer the rotation to the housing assembly 200. With the aid of a worm drive 219,.which is connected with the operating knob 203 and which acts in a direction perpendicular to the worm drive 106 on the joint part 208, the housing assembly is then levelled in the transverse direction. In this, the joint part 207 with the calibrated plates217 and 218 for measuring the angle of elevation istilted by the amount of the angular diviation of the elevation axis relatively to the joint part 206. A turning moment about the vertical axis 2001 of the housing assembly 200 then becomes effective, which by means of the lever arm 214 causes rotation of the head 215 relative to the remainder of the housing assembly 200. The panoramic telescope 300 coupled rigidly with the head 215 thus moves out of its previously set lateral position by the amount of the correction value for the lateral setting, so that the weapon has to be set afresh to the desired azimuth. As a result of the lateral movement of the weapon, the housing assembly 200 again loses its levelling, and there occurs also an alteration in theheight of the adjusted weapon. The adjusting procedure has thus to be repeated until the three mutually independent requirements namely levelling, desired azimuth and desired angle of elevation of the gun are all given simultaneously. By the special arrangement of the measuring graduations for the angle of elevation inside the jointpart 207 and at the lever arm 214 in the levelled condition of the housing assembly the angle of elevation about the horizon is always indicated. Y

It is possible, in place of the described levelling by manually operable drive after each alteration in the setting, to control the levelling automatically, synchronously with the alteration in the setting. For this purpose it is only necessary to couple with the levelling devices of the spirit levels 204 representing the horizontal a generator system which controls motors connected to the operating knobs 203 and 105 or directly to the ing digital indication of the angles measured is shown in FIG. 3. Electrical signal generating means 6 lying in front of the calibrated plate 218 and electrical signal generating means E located behind the calibrated plate.

217 are connected through connector S and cable K to digital indicator A.

FIG. 4 shows an arrangement for conducting an image of the graduations on calibrated plates 217 and 218 through joint part 207 and head 215 by illumination by light source L, on the end of optical conducting means F fed through apertures D.

The described embodiment has an improved mechanical construction for a sighting arrangement with automatic azimuth correction and angle of elevation measurement in a plane perpendicular to the horizontal, by means of which with judicious choice of dimensions high requirements of accuracy can be fulfilled. The device has an angular measurement system of high resolving power. In particular, the device makes possible digital indication of the measured angle values, for the purpose of indirect aiming of artillery weapons.

What is claimed is:

1. A sighting device for an artillery weapon which is adjustable about an elevation axis with respect to a support base, comprising:

a. a support means attachable to said support base for rotatably mounting a shaft (201) in parallel alignment with said elevation axis and means rotatably coupling said shaft to said weapon in such a manner that said shaft rotates in concert with rotations of said weapon about said elevation axis;

b. a universal joint having a first part (206) rigidly carried by the shaft;

c. a housing (200) for receiving the universal joint, the housing comprising a body portion and a head which is rotatable relative to the body portion and which is connected to the universal joint, the housing being provided with leveling means to permit the housing so to be leveled with respect to said shaft such that the axis of said rotation extends in a vertical direction;

(1. a second part (207) of the universal joint being mounted on the first part to be rotatable relative thereto about a first joint axis perpendicular to the longitudinal axis of the shaft, said second part defining a second joint axis perpendicular to said first joint axis, and being mounted on a mounting portion (214) of said head to be rotatable 'about said second joint axis; and

e. an angle measuring device comprising a first element (217) carried by the second part to be situated within the universal joint and to extend transversely of said second joint axis of the second part, and a second element (218) which is rotatable relative to the first'element and which is rigidly connected to the mounting portion (214), the first and second elements being provided with an arcuate indicating means having its center of curvature on the second joint axis of the second part, the two elements and said indicating means indicating the angle of elevation of means on the head for mounting a telescope, and a further angle indicating means to indicate the azimuth angle of the telescope.

2. A device as claimed in claim 1, wherein the mounting portion comprises a lug integral with the remainder of the head, the remainder carrying the telescope mounting means.

3. A device as claimed in claim 1, wherein the centers of curvature are situated substantially at the point of intersection of said second joint axis and said first joint axis.

4. A device as claimed in claim 1, wherein the universal joint further comprises a third part connected between the first part and the housing, the third part being mounted to be rotatable relatively to the first part about the axis of said shaft and being provided with two mutually coaxial bores receiving mounting means of the housing to permit the housing to rotate about the common axis of the bores, the common axis coinciding with said first joint axis.

5. A device as claimed in claim 4, comprising manually operable drive means to cause the housing to rotate relatively to the third part about said perpendicular axis.

6. A device as claimed in claim 4, comprising a manually operable driving means for causing the third part to rotate relatively to the first part about the longitudinal axis of the shaft.

7. A device as claimed in claim 1, wherein at least one of the parts of the universal joint comprises a partspherical socket member.

8. A device as claimed in claim 1, wherein the angle indicating means each comprise electrical signal generating means for generating electrical signals representative of the angles sensed by the indicating means, and digital read out means to provide a visual indication of the angles.

9. A device as claimed in claim 1, wherein the angle indicating means are each provided with visible graduations and with optical image conducting means for conducting an image of the graduations to a respective reading location. 

1. A sighting device for an artillery weapon which is adjustable about an elevation axis with respect to a support base, comprising: a. a support means attachable to said support base for rotatably mounting a shaft (201) in parallel alignment with said elevation axis and means rotatably coupling said shaft to said weapon in such a manner that said shaft rotates in concert with rotations of said weapon about said elevation axis; b. a universal joint having a first part (206) rigidly carried by the shaft; c. a housing (200) for receiving the universal joint, the housing comprising a body portion and a head which is rotatable relative to the body portion and which is connected to the universal joint, the housing being provided with leveling means to permit the housing so to be leveled with respect to said shaft such that the axis of said rotation extends in a vertical direction; d. a second part (207) of the universal joint being mounted on the first part to be rotatable relative thereto about a first joint axis perpendicular to the longitudInal axis of the shaft, said second part defining a second joint axis perpendicular to said first joint axis, and being mounted on a mounting portion (214) of said head to be rotatable about said second joint axis; and e. an angle measuring device comprising a first element (217) carried by the second part to be situated within the universal joint and to extend transversely of said second joint axis of the second part, and a second element (218) which is rotatable relative to the first element and which is rigidly connected to the mounting portion (214), the first and second elements being provided with an arcuate indicating means having its center of curvature on the second joint axis of the second part, the two elements and said indicating means indicating the angle of elevation of means on the head for mounting a telescope, and a further angle indicating means to indicate the azimuth angle of the telescope.
 2. A device as claimed in claim 1, wherein the mounting portion comprises a lug integral with the remainder of the head, the remainder carrying the telescope mounting means.
 3. A device as claimed in claim 1, wherein the centers of curvature are situated substantially at the point of intersection of said second joint axis and said first joint axis.
 4. A device as claimed in claim 1, wherein the universal joint further comprises a third part connected between the first part and the housing, the third part being mounted to be rotatable relatively to the first part about the axis of said shaft and being provided with two mutually coaxial bores receiving mounting means of the housing to permit the housing to rotate about the common axis of the bores, the common axis coinciding with said first joint axis.
 5. A device as claimed in claim 4, comprising manually operable drive means to cause the housing to rotate relatively to the third part about said perpendicular axis.
 6. A device as claimed in claim 4, comprising a manually operable driving means for causing the third part to rotate relatively to the first part about the longitudinal axis of the shaft.
 7. A device as claimed in claim 1, wherein at least one of the parts of the universal joint comprises a part-spherical socket member.
 8. A device as claimed in claim 1, wherein the angle indicating means each comprise electrical signal generating means for generating electrical signals representative of the angles sensed by the indicating means, and digital read out means to provide a visual indication of the angles.
 9. A device as claimed in claim 1, wherein the angle indicating means are each provided with visible graduations and with optical image conducting means for conducting an image of the graduations to a respective reading location. 